Means for graveling oil wells



Sept. 19, 1939. L. A. LAYNE MEANS FOR GRAVELING OIL WELLS m E. m h cw A 6N w L wmm e V T M S E 4 2 U AU 5 E B L m 9 5 1 g u A Q e F Patented Sept. 19, 1939 PATENT OFFICE 2.173.119 MEANS FOR GRAVELING on. WELLs Leslie A. Layne, Texas Comm Houston, Tex, alsignor to The a corporation of Delaware Application August 16, 1937, Serial No. 159,377

12 Claims.

This invention relates to a means and method of graveling oil wells under pressure where it is desired to deposit the gravel about the screen or strainer in order to form a filter bed.

The problems encountered in an operation of this sort involve the introduction ing fluid or release of the pressure from the formation. It is therefore necessary that equipment he provided by which the gravel and its carrier liquid may be introduced and at the same time a circulation be maintained by which the well may be washed and the sand, sediment and the carrier liquid may be returned to the surface. It is also desirable to deposit an excess of the gravel in the casing in the well bore above the screen so that as the gravel packs down and settles into its permanent position there will have been a sufiicient amount of gravel in storage to compensate for the settling so that the strainer cient to prevent caving of the formation and to also overcome the formation pressures which are encountered so as to avoid a blow-out of the well.

It is one of the objects of the invention to provide a means and method of graveling a well wherein the gravel may be deposited hydraulically while the well is maintained in closed condition.

Another object of the invention is to provide an arrangement of the casing, production string and the wash line whereby the various operations of graveling the well under pressure may be carried out.

Another object of the invention is to provide a well assembly wherein the gravel may be deposited in the well about the strainer while a circulation of liquid is maintained inside of the strainer.

Another object of the invention is to provide an arrangement whereby suitable openings through the strainer or production string are provided which openings will be blocked when a predeterliquid so as to indicate to the operator that sumcient gravel has been deposited.

Another object of the invention is to provide a well bottom assembly which will fllanal when sumcient gravel has been deposited so that the a from the strainer so that the 2 and has penetrated to a productive packer and seal may be set to trap the gravel in Positi n.

Another object of the invention is to provide a string of strainer pipe wherein openings are provided through the strainer at a point spaced 5 blocking of these openings may be used to indicate the deposit of sufllcient gravel in the well.

Still another object of the invention is to provide a graveling apparatus for wells in connection with a mechanism for circulating an additional stream of fluid through the well.

It is also an object of the invention to direct a stream of carrier liquid and gravel into a well bore between a string of strainer pipe and a well 16 casing wherein there are openings through the strainer pipe to admit the carrier liquid and exclude the gravel so that ,the returns will flow upward through the strainer string in combination with devices for directing this return flow so through any one of several discharge outlets from the well head.

'Another object is to deposit gravel between the strainer and the casing so as to form a filter for material entering the casing. 25

Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawings, wherein:

Fig. 1 is a side elevation of a well which is being so graveled under pressure and wherein a sufllcient volume of gravel has been deposited.

Fig. 2 is a broken side elevation of a different form of casing head than is shown in Fig. 1, which head embodies a blow-out preventer.

Fig. 3 shows a side elevation somewhat similar to that shown in, Fig. 1 but illustrates a packer for closing cit the area between the production string and the casing so that the gravel may be permanently located in position.

In Fig. 1 the well bore is indicated generally at formation 3. The well bore down to an elevation just above the productive formation has been cased oil! by the casing 4, the lower end of which is sealed with a body of cement I to prevent the escape of fluid upwardly around the casing.

The productive formation 3 has been underreamed either with a mechanical under-reaming tool or by hydraulically washing away the formaso tion so as to provide an enlarged chamber 1. This chamber I is to be provided with a body ofgravelisoastoiormaiilterbed. It is well understood, of course, that the casing landthechamlierIarefllledwithaslushor drilling mud during these operations and the production or strainer string I2 is assembled and lowered into the well bore as shown in Fig. 1.

This string comprises a set shoe l5, suitable length of strainer pipe l8, liner l1 and a perforate section of pipe l8 above the liner to which the remainder I9 of the string is connected.

This string projects through the casing head 20 which is joined to the upper end of the casing 4 and a seal 2| is provided in'the casing head about the pipe It. 'A valve 23 may be incorporated in the upper end of this string below the Christmas tree fitting 24. The branch pipes 25 and 28 may be connected to the fitting 24 and each of these may carry avalve 21. A valve 30 may be positioned on the top outlet 3|. of the fitting 24 and a stuifing box 33 thereon may receive the wash line or tubing string 34.

During the graveling operation it is desirable to maintain a circulation of liquid through the inside of the strainer string l2 and to accomplish this a pipe 38 is connected to the wash line 34 and a pump 38 may be utilized to create a circulation downwardly through the pipe 34. As seen in the middle and lower portion of Fig. 1 the wash line 34 may extend downwardly through the strainer string to any desired elevation and the lower end of this wash line may or may not be connected in the shoe l5. The casing head 20 is provided with the discharge line 48 and the inlet line 4|. A valve 42 is provided on the discharge side.

The line 4| extends to a graveling apparatus indicated generally at 45 which may include a storage chamber 46 and a hopper 41 leading thereto by which the gravel is introduced into the container. A pump 58 is connected to the piping 5| so that a flow of liquid may be directed through the pipe 52 into the storage tank 45 and the control of this flow may be regulated by a valve 54. On the other hand, some of the flow from the pump may pass through the piping 58 and may be regulated by the valve 51. The discharge from the receiver 45 will be through the piping 58 which may be opened or closed by a valve 59.

It seems obvious that by the manipulation of these valves any desired proportion of the liquid may be discharged either into or around the graveling apparatus as desired.

In operation the form of the invention thus described may be utilized by lowering the strainer string |2 into position in the well bore and then circulation may or may not then be had by operation of the pump 38. If it is desired to wash some of the drilling mud from the well and to thus reduce the specific gravity of it and accordingly reduce the pressure on the formation, clear Water may be circulated. In some instances it is desirable to wash the face of the formation 3 so as to remove the penetration of the drilling mud therefrom. This washing operation may be accomplished by directing the fiow downwardly through the wash pipe and outwardly through the set shoe l5 or the wash pipe may be raised somewhat and discharged into the strainer I6 so as to wash anymud out of the strainer.

In some instances it may be desirable to gravel the well with the drilling mud still in position due to the fact that high pressures have been encountered and the weight of the column of drillingmud is necessary in the well to overcome these pressures during. the graveling operation. In either event, when the parts have arrived at the position shown in Fig. 1, the pump 5|! may be started and the graveling apparatus 45 brought into action to introduce gravel carried by a liquid through the pipe 4| into the casing head 20. This flow of liquid and gravel will move downwardly in the annular area 43 between the casing and the strainer string, and as seen in Fig. 1, the body of gravel has been thus deposited. The carrier liquid thus introduced into the well .along with the gravel will flow through the strainer I6 and upwardly through the strainer string l2 if the valve 42 is closed. One of the valves 21 may thus be opened and returns discharged therefrom. In some instances where the casing covers a productive formation, the casing will be perforated and in such an arrangement the filter will be around the strainer inside the casing.

When the elevation of the gravel in the well bore rises above the perforate section l8 there will be an immediate increase in pressure due to the fact that the carrier liquid must thus be forced through the upper portion 60 of the gravel before it can enter the perforate section l8. This increase in pressure will be readily noted on the pressure gauge 6| on the pipe line 4| and in this manner a signal will be transmitted to the operator to indicate to him that a suflicient body of gravel has been deposited, it being understood of course that this perforate section H! has been located in the strainer string |2 at the elevation at which it is desired to position the top of the body of gravel. In some instances it may be at the base of the casing or it may be near the surface of the well depending on the amount of settling which is anticipated.

After the gravel has been deposited, the pump 38 may be placed in operation so as to circulate clear water downwardly into the well bore in order to wash the mud or sediment from the deposit of gravel. This washing operation may be carried on by continuing the circulation and gradually raising the wash pipe so that clear water is driven outwardly, first, through the bottom of the set shoe l5 and then progressively upwardly through the strainer l6. This wash- I ing operation may be carried on until the returns from the well indicate that the mud has been removed. If desired, the valve 42 may be opened during this washing operation and the returns allowed to pass out through the discharge pipe 40.

It seems obvious that the various valves may be manipulated as desired during these various operations in order to direct the inlet and outlet from the well to the desired area to accomplish the results in mind.

A pressure gauge 62 is shown on the wash line 34.

Another manner of introducing the gravel using the apparatus of Fig. 1 would be to continue the circulation of water through the wash pipe 34 while the gravel is being deposited. The valve 42 could thus be opened to allow a return of the carrier liquid and one of the valves 21 could be opened to allow a return of the washing liquid. In this manner a continuous circulation inside of the strainer would prevent any deposit of sand or sediment therein and the signal to the operator would be given when the gravel had been deposited to an elevation above the perforate section |8, or if desired, the valve 21 could be closed so that the liquid from the pump 38 would be continuousuly discharged either through the strainer |6 or the perforate section l8. ,In this manner this added circulation could beused to assist in removing any sand or sediment loos- 2,173,119 3 ened from the formation 3 and to also assist in through the strainer string at the desired elevawashing the well during the graveling operation. tion.

In s me i an h W h p p 4 might not Broadly, the invention contemplates a means be in place during the graveling operation and the valve 23 might thus be closed to compel discharge through the outlet 40.

It is contemplated that the mechanisms shown will be used either independently or in conjunction with each other and that the valves and piping will be man pulated to obtain the desired results. I

In Fig. 2 a slightly modified form of casing I head has been shown in that it embodies a blowout preventer construction 10 above the outlet 40. Blow-out preventers of this type are well known in that they have horizontally movable ram' members which may engage each other to close ofi the well if there is no pipe in the well or the rams may be recessed to engage about the pipe and form a seal therewith in event there is a pipe in position. of course suitably shaped rams will be provided on the preventer.

The apparatus shown in Fig. 3 is quite similar to that described in connection with Fig. 1, except that a packer has been incorporated in the strainer string l2 and by manipulation of the upper portion is of this string the packer may be set to form a seal between the casing 4 and the strainer string after the gravel has been deposited. A drilling valve 8| is shown also on the casing 4 below the casing head 20 and some of the Christmas tree fittings have been omitted so that the strainer string is shown as supported by a suitable elevator 83 through a connection to a swivel 84. The discharge line 36 from the pump 38 leads into the swivel. With the construction of Fig. 3, the pipe inside of the well may be raised and lowered at will during the washing and graveling operation and the wash pipe 34 is incorporated as a part of the setting string 85 by which the entire well bottom assembly and the packer are set in the well.

"It will be well understood that with the construction of Fig. 1 the returns from both of the pumps may be through the strainer string or through the liner as desired, and after the graveling operation has been completed, if the mud wall on the face of the formation 3 hasnot been broken up sufliciently to permit the inflow of oil then the wash'pipe 34 may be removed and a swab or baile'r run into the well to reduce the pressure on the face of the formation in order to break down the mud wall. If the well comes in flowing after the graveling operation, however, and it is desiredto find out whether the mud wall has broken down, the graveling pump may be started up to determine whether or not any more gravel may be introduced into the well because some of the gravel may have settled into the chamber 1.

If the-returns are to be through the letting in string I! of Fig. 3, the pipe 36 may be disconnected to allow the discharge where the pump 33 is not in use or connected.

This settling would have uncovered the perforate section II and would thus permit the introduction of an amount of gravel equal tofthe settiing which has taken place before the pressure on the lines would jump to indicate that the perforate section was again blocked oif by gravel.

This perforate section l8 can best be indicated as- ,a tell-tale section-and while a ioint of strainer has been shown in the drawings, it is to be under-,

stood that the same result may be accomplished by merely providing one or more openings and method by-whioh gravel may be introduced into a well bore while there is pressure on the well bore and while the well head is completely closed in.

What is claimed is:

'1. A well having head on said casing,a strainer and liner string in the ,well, a seal through said head about said string, means to introduce gravel under pressure between said casing and said liner string, and

separate means to circulate liquid into and out of said well.

2 A well havinga casing therein, a casing head on said casing, a strainer and liner string 1 in the well, a seal through said head about said string, means to introduce gravel under pressure between said casing and said liner string, and tell-tale means on said string above said strainer to indicate when the elevation of the gravel reaches such means.

3. The combination of a well casing, a'casing head thereon, a production string of pipe sealed in said head, spaced strainer areas in said string, an inlet to said casing, means to introduce gravel and a carrier liquid through said inlet between said casing and string, an outlet on said casing for the carrier liquid, additional means to introduce liquid into said production string to discharge through said strainer areas, and pressure indicators on both of said means to indicate an increase in the pressures when the gravel being deposited covers both strainer areas.

4. The combination of a well casing, a casing head thereon, a production string of pipe sealed in said head, spaced strainer areas in said string, an inlet to said casing, means to introduce gravel and a carrier liquid through said inlet between said casing and string, an outlet on said casing for the carrier liquid, additional means to introduce liquid into said production string to discharge through said strainer areas, and packer means carried by said string to seal the inside of said casing above said strainer.

5. In an oil well assembly a casing, a string of pipe therein, a lower strainer section in said pipe below said casing, an upper strainer section in said pipe within said casing and spaced from said lower strainer section, and means to deposit gravel to an elevation above said upper strainer section so that there is a surplus of gravel ready to settle into the area about said lower strainer.

6. A well casing, a strainer string of pipe therein, a. tubing inside of said pipe, means to introduce liquid into said tubing,- means to introduce liquid and gravel into said casing, an outlet from said casing, and an opening through said strainer string to be blocked by the depositing of gravel in said casing whereby the increase in pressure of said first means indicates the level of the gravel. i

'7. In a well assembly a casing, a strainer string, a strainer on the lower end of said string, a wash line in said string, means to introduce liquid through said wash line, said string being provided with a plurality of perforations spaced above said strainer and within said casing, discharge outlets from the top of said string and means to introduce gravel around said string.

8. The combination of a well casing, a casing a casing therein, a casing head thereon, a production string of pipe sealed I in said head, spaced strainer areas in said string,

an inlet to said casing, means to intr duce gravel and a carrier liquid through said inlet between said casing and string, the upper 01 said areas comprising a tell-tale inlet to said production string for the carrier liquid so that it may discharge from the well through said string, and packer means carried by said string to seal the inside of said casing above said strainer. 9. The combination of a well casing, a casing head thereon, a production string of pipe sealed in said head, spaced strainer areas in said string, an inlet to said casing, means to introduce gravel and a carrier liquid through said inlet between said casing and string, the upper of said areas comprising a tell-tale inlet to said production string for the carrier liquid so that it may discharge from the well through said string.

10. The combination of a well easing, a strainer string therein, a strainer in said string, a second strainer in said string disposed entirely within said casing, and means to form a filter of divided material in the annular spacearound said second strainer and within said casing.

11. A well bottom assembly comprising a set shoe, strainer, liner and packer, a setting tool and wash pipe connected. therewith, an operating string to manipulatesaid tool, means to discharge gravel in the well about said strainer, said setting tool being adapted to thereafter set said packer.

12. A well bottom assembly comprising a set shoe, strainer, liner and packer, a setting tool and wash pipe connected therewith, an operating string to manipulate said tool, means to discharge gravel in the well about said strainer, said setting tool being adapted to thereafter set said packer, and tell-tale openings through said liner above said strainer to indicate the level of gravel about said strainer and liner.

LESLIE A. LAYNE. 

